1. Field of the Invention
The present invention relates to a suspension spring adjusting apparatus of a hydraulic shock absorber.
2. Description of the Related Art
Conventionally, as a suspension spring adjusting apparatus of a hydraulic shock absorber, there is a structure in which a piston rod is inserted to a cylinder, a spring adjusting jack is provided in an outer periphery of the cylinder, a jack chamber is provided in a spring adjusting case in which the spring adjusting jack is fixed to an outer periphery of the cylinder, a plunger is provided in the jack chamber. A pump supplying a hydraulic pressure to the jack chamber is installed in the spring adjusting case, a motor driving the pump is provided in the spring adjusting case, the motor is covered by a case cover attached to the spring adjusting case, and a suspension spring is interposed between a spring receiver supported to the plunger of the spring adjusting jack and a spring receiver provided in a piston rod side.
Alternatively, Japanese Utility Model Publication No. 63-19204 (patent document 1), discloses a structure wherein a vehicle body side is provided with a driving means (a motor or the like) for adjusting a damping force of a hydraulic shock absorber, and a mounting mating surface between the vehicle body and a cover (a seal cap) is sealed by a seal ring, at a time of covering the driving means for adjusting the damping force by the cover attached to the vehicle body side.
In the suspension spring adjusting apparatus of the hydraulic shock absorber, in the case that the structure described in the patent document 1 is employed as the seal structure between the spring adjusting case and the case cover, a high-pressure washing water of a high-pressure car wash or the like is directly brought into contact with an outer edge of the mounting mating surface between the spring adjusting case and the case cover, and the load of the direct intruding water against the seal ring becomes excessive.
There can be considered a structure which prevents the high-pressure washing water from being directly brought into contact with the outer edge of the mounting mating surface between the spring adjusting case and the case cover, by faucet joining an annular protruding portion provided in an outer peripheral side of the case cover to a portion around an annular step portion provided in an outer peripheral surface of the spring adjusting case. In this case, the annular step portion and the annular protruding portion are worked respectively in the spring adjusting case and the case cover, and a fixed working precision is necessary for the faucet joint.
In this case, in the conventional suspension spring adjusting apparatus of the hydraulic shock absorber, it is necessary that the mounting boss is provided in a rising manner in the spring adjusting case, and the end surface forming the motor mounting seat surface of the mounting boss is worked in a flat shape, as the mounting structure of the motor to the spring adjusting case.